You will begin this tutorial by making two changes to the database, both of which require corresponding changes to the data model that you created in the Getting Started with the Entity Framework and Web Forms tutorials.In one of those tutorials, you made changes in the designer manually to synchronize the data model with the database after a database change.In a production application, you would provide a specific error message when a database constraint prevents a deletion, or you would specify a cascading delete.
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Like the Getting Started series, this tutorial series uses the ASP. This lets you combine the advantages of an n-tier approach with the benefits of using a Web Forms control for data access.
NET Web Forms model and assumes you know how to work with ASP. The control gives you more flexibility in other ways as well.
This makes it possible for you to provide the business-logic class with a reference to any object that implements the repository interface.
For normal operation, you provide a repository object that works with the Entity Framework.
In the third tutorial in this series you will add sorting and filtering functionality to the application.
The pages you create in this tutorial work with the entity set of the data model that you created in the Getting Started tutorial series.
You need to create the relationship and update the data model so that the Entity Framework can automatically handle this relationship.
In the database diagram, right-click the table, and select Relationships.
Because you write your own data-access code, it's easier to do more than just read, insert, update, or delete a specific entity type, which are the tasks that the control is designed to perform.
For example, you can perform logging every time an entity is updated, archive data whenever an entity is deleted, or automatically check and update related data as needed when inserting a row with a foreign key value. For example, when you update a department, you might need to validate that no other departments have the same administrator because one person cannot be administrator of more than one department.
To make it easier to do that, you will create a view in the database.